Document FR-A-2 476 001 discloses a vehicle back seat of that type in which the headrest is tilted from its in-use position to its folded-away position manually prior to the seat back being tilted down into its folded-away position, thereby reducing the outside dimensions of the seat back.
Thus, in order to tilt the seat back down into its folded-away position, two prior operations are required: firstly the headrest must be folded down manually, and then the first control member needs to be actuated, and that is irksome.
In addition, if the user forgets to fold down the headrest before folding down the seat back, then the headrest is liable to interfere with other elements of the vehicle, in particular with the seat proper of the same seat or with the front seats.